The invention refers to a method of information processing for the production of a printing form for printing the image of an original, especially the production of an intaglio printing form, wherein image signals corresponding to the information contents of the original and aquired by scanning the original and digitalized thereafter are stored in a memory and processed in a computer and wherein the information is thereafter edited in a form suitable for the production of the printing form.
A method of information processing is known from the German Patent Letter No. 1 193 534, which serves the recording of the digitalized image signals with a continuously adjustable recording scale on a recording medium. The original and the recording medium for the recording of the stored image signals are mounted on drums of like diameter and like rotational speed. The stored image signals are called with freely selectable rate, while the called image signals control the recording elements and while the feed rate of the scanning elements are adjusted with respect to the original corresponding to the recording scale determined by the ratio of the calling rate and the storing rate, respectively, and corresponding to the line density selected for the recording. If the information processing is to serve the production of colour separations, the known process provides that the image signals of the individual colour separations are submitted to a colour correction in a computer either before their storing in said memory or after the destoring from said memory. In the first case, the memory already stores the corrected colour separation image signals, whereas in the latter case the uncorrected colour separation image signals are stored.
The known method does not yet provide to perform the entire information processing starting from the original and leading to the printing form ready for print in pure electronic manner independently on the printing process. Up to now, usually colour separations in form of black-and-white films in the desired final format of the printing form have been produced from coloured originals by means of a camera or by means of a drum scanner. Different information variations had to be performed on these films by means of the reproduction technology, i.e. retouchings and mountings had to be performed manually. For example, it was necessary to perform retouchings on negative or positive films in dependency on the type of detail to be retouched. The retouched colour separations were the basis for coloured control copies, which allow a judgement over the printing result to be achieved during the printing process. It proved, however, that often further retouching corrections are necessary. The finished and checked colour separations have then to be optically printed on special film material, before they can be scanned for example by the scanning unit of an engraving machine for the production of an intaglio printing form.
The previously only in coarse manner discussed operational steps, which are necessary in to-day reproduction, are extremely intensive with respect to labour and costs; the main disadvantage thereof, however, resides in the fact that after the provision of the originals for a page to be printed usually a considerable time interval passes away, before the printing form is ready.